The present invention relates to electronic price label (EPL) systems used in transaction establishments, and more specifically to a communication device and method for EPL systems.
EPL systems typically include a plurality of EPLs for each merchandise item in a store. EPLs typically display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. A store may contain thousands of EPLs to display the prices of the merchandise items. The EPLs are coupled to a central server from where information about the EPLs is typically maintained in an EPL data file. Price information displayed by the EPLs is obtained from the PLU file.
EPLs today may be wired or wireless. Wireless EPLs may employ infrared or radio frequency (RF) transmitters. EPLs systems of the assignee of the present invention employ RF transmitters and modulated backscatter techniques. An EPL computer transmits polling signals to one or more EPLs. In order to respond to the poll, an EPL "reflects" the polling signal back to the EPL computer within a predetermined time interval of receiving the polling signal. A good analogy of the RF modulated backscatter acknowledgment signal is a mirror reflection. If two men face each other, one with a flashlight and the other with a mirror, the man with the mirror can send an acknowledgment to the man with the flashlight by reflecting the beam of light back to him. Similarly, the man with the mirror may indicate the opposite by not reflecting the light of the flashlight.
Modulated backscatter techniques are taught in U.S. Pat. No. 5,640,683, to Evans et al., entitled "Modulated Backscatter Wireless Communication System Having An Extended Range", issued Jun. 17, 1997. This patent is hereby incorporated by reference.
Remote control and communication with a host EPL computer system would be desirable anytime the EPL system installer, user, or administrator is performing EPL related tasks away from the host EPL computer. One such task that might be performed by an EPL system administrator is adding or removing an EPL tag to a shelf. Normally, the administrator must perform administrative tasks at the host processor before placing the tag on the shelf. These tasks include initializing the EPL tag and adding the ID of the EPL tag to an EPL database. It would be advantageous to perform these administrative tasks remotely as the system administrator is adding or removing the tag from the shelf.
Hand-held terminals have been developed which communicate with the EPL computer, effectively allowing remote communication with the host processor. However, these terminals are costly and can introduce noise that may interfere with the EPL system. When a hand-held terminal device is introduced that does not share the same communication protocol or hardware as the EPL system, there is some likelihood that the device will interfere with existing EPL system communication. In order to avoid interference, the EPL system must sacrifice performance by giving up radio frequency bandwidth to the device.
Therefore, it would be desirable to provide a communication device and method for EPL systems that would allow an operator to remotely control the EPL computer from anywhere in a store using the existing EPL infrastructure.